Outlook emails sent to Cox addresses are blocked by the Cox servers
Cox SMTP servers block outgoing email from Outlook. (I am still using 2016.) The spam filter, providef by Cloudmar,k uses a backward DNS check which reportd SPAM erroneously..
Forum Discussion
This has been going on for months!
If the spam filter is blocking you, it means there is something in your email that is causing it. Delete ALL email in your outbox, wait for 6 hours, for the smtp server to clear, then try to send yourself a test message. The word TEST in the subject line, and the word TEST in the body of the message.
That is one more reason not to use Cox email. I never had such a problem with Gmail or Proton. Could you change?
Don't know why people are having issues, Setup the mail software properly, (Avoid thunderbird, it **), and it just works. I have had WLM working since windows 7, without issue.
I used to use Thunderbird and it was great. Maybe it isn't being developed anymore? But then I found this article about a come back. Either way it is better then Mac Mail IMO.
Maybe outlook.live.com is your best bet?
